Drill collar for well drilling

API 7-1 Drill collar

We supplyslick drill collars,spiral drill collarsandnon-magnetic drill collars; their sizes are from 3-1/8 to 11 inches. Besides the drill collars in the table below, we can supply other drill collars at customers' request.
Function :

1.Apply drill pressure to drilling bit .

2.Ensure the necessary strength in the circumstances of compression.

3.Lighten the vibration, swing and Run out of drilling bit to make a steady work status .

4.Control well deviation
Materials:
Drill collars are manufactured from AISI 4145H modified steel, and are supplied in the "as rolled" surface finish condition. Alternative surface finishes are available.
Trepanning and Heat Treatment:
Drill collars are trepanned and drifted to API Spec 7-1. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7-1 requirements. A hardness range of 285-341, Brinell hardness and Charpy "V" notch minimum impact strength of 40 ft-lb at 70 F are guaranteed one inch below the surface.
Traceability:
Drill collar material and process traceability are maintained from receipt of the mill's certified raw material to completion of manufacturing. Serial numbers are die stamped on bar bodies.
Rigid Inspection Procedures:
We inspect all our drill collars to ensure compliance with API SPEC 7-1 standards. These inspections include visual dimensional checks as well as ultrasonic inspections over the entire body of the drill collar.
Cold Rolling:
Drill collar thread roots, as well as elevator recess upper radius, are cold-rolled. Cold rolling creates a compressive recess upper radius stress condition that increases fatigue life by minimizing crack initiation.
Phosphate-coated or Copper Plating:
All connections are phosphate-coated or copper plated to improve resistance to corrosion.
Slip Groove, Elevator Groove and Size:
Lake offers optional slip and elevator recesses to improve handling efficiency and safety. Unless otherwise specified, slip and elevator recesses are machined in compliance with API spec 7-1 guidelines.
Thread Protectors:
Our company offers steel, cast steel and plastic steel thread protectors for its drill stem products.

Lake Petroleum Technology Co., LTD (hereinafter as Lake Petro company) is located in Dongying City, which is famous for Shengli Oilfield and the largest manufacturing hub of petroleum equipment in China.

Lake Petro company is a professional supplier of various oilfield equipment, including oil drilling and service equipment,oil production equipment,OCTG ,wellhead & downhole tools and spare parts with API certification. Following the principle of "quality first, science and technology innovated, people oriented", every Lake Petro person is sparing no effort to provide the customers with best products and services. Through efforts of Lake Petro staff, our products have already been exported to USA, South America, Africa, Middle East, Russia and some other countries (regions). With super quality, reasonable price and professional service, Lake Petro company has become VIP (assigned) supplier and built strategic partnership with some coutries' national petroleum companies.

Lake Petro company takes "providing the most qualified products, most competitive prices and most professional service for every customer " as its mission. We are striving and aiming to be one of the most professional oilfield equipment suppliers in China. We sincerely welcome customers and friends domestic and abroad come to create a prosperous future with us.